The present invention relates generally to the field of water pump filters and more particularly, to a removable strainer for an evaporative cooler.
Evaporative coolers are well know and used in warm arid climates to cool the air. Conventional evaporative coolers work by drawing air from outside through a rigid media soaked with water. As the air flows through the media soaked with water, the water is evaporated by the outside air thereby lowering the temperature of the air. The cooled air is then directed into the area to be cooled.
Conventional evaporative coolers include a number of elements stored in a housing. These elements typically include an air blower, a media pad, a water distribution system, and an electric motor. The water distribution system includes a water pump that draws water from a collection pan in the bottom of the housing and pumps the water through tubing to the top of the media pad or pads. Some of the water in the media pads is evaporated as air is drawn through the media. The remaining water that is not absorbed in the media returns to the collection pan in the bottom of the housing. In this manner the water is recirculated. Fresh water is added only to replace the water that has been evaporated.
It is not desirable to circulate any debris, that may fall into the collection pan. The debris can both clog the pump and/or the media. Debris may fall into the housing during installation of the evaporative cooler or during replacement of the media. Additionally, since the water is being recirculated any minerals in the water tend to build up overtime in the collection pan. One method of removing the mineral buildup is to intentionally replace the water in the collection pan on a periodic basis. To minimize debris from entering the water pump a filter or strainer may be used. One such filter or strainer is disclosed in U.S. Pat. No. 3,046,900 issued on Jul. 31, 1962 to Pollak which illustrates a two piece filter element that fits on top of a portion of the pump. Since this filter only covers the top of a base portion of the of the water pump, debris that is on the bottom of the collection pan may still enter the pump.
Another attempt to introduce a filter is disclosed in U.S. Pat. No. 4,856,971 issued on Aug. 15, 1989 to Koble. The filter disclosed in Koble includes a number of thin slits that are formed directly through the lower portion of the base. Similarly, Koble does not filter any debris located on the base of the pan.
Since, the collection pan is typically not completely planar debris is able to enter below the lower edge of the housing. As soon as an opening exists between the lower edge of the water pump and the collection pan, debris can enter this opening and be circulated by the pump and/or clog the pump. Additionally, since the slits are part of the pump itself if the slits become clogged it is necessary to remove the entire pump in order to clean the filter portion.
Accordingly, there is a need for a filter for a water pump that filters out debris located on the bottom of the collection basin. There is also a need for a filter that can be easily removed from the water pump housing for cleaning and or replacement.